For one reason or another, but unquestionably for worse rather than better, we tend to think of our selves, beings of unique personal identity, as disembodied—or at the very least, to relegate the bodily dimensions of our consciousness to the status of a contribution to the self, but not an integral part of it. We “live” in our heads, with and through and among the silent articulation of meanings linguistically captured and expressed in unvoiced words, spoken to and by the self. In short, we construct a self out of the verbal, and now, even more than before, find our words through various artificial and social media.  That we think by speaking to ourselves is no problem. But that we (perhaps unconsciously) confine the conception of the self to the places constituted through that inner dialogue—deriving the words by which it is composed from our smartphones and computers, through television, streaming services and podcasts—does not just separate us from the greater reality of our selfhood by reducing us to psychological subjectivity,  it exposes the determination of the self to inhospitable forces.
For with this circumscription of self in thought, however obscured the separation may be in the mind of any given individual, comes an unbridgeable chasm between the self—as a mind—and the body, as an instrument.  What we claim as belonging to our lives, then, are—in work and play—investments of the mind. Meanwhile, the operations of the body become mechanical and guided by a principle of efficient subservience to the mind.  That we may enjoy sports or exercise, the playing of an instrument or dancing, the caressing of and playing with pets, the relaxation of massage, or the sensual intimacies of the bedroom, does not always or inevitably indicate a cohesion of mind and body; for these “activities” (even in being so named) typically become nothing more than a perceived catharsis against the rigours of bodily servitude to the abstract impositions of a disembodied self. The cathartic need, in other words, is not an impulse innate to being human, but rather the rebellion of a nature that’s been tortuously contorted away from its own proportion.
For we are bodily beings—intellectual beings who, naturally, dwell through a linguistic ποίησις, but who are imperilled as a whole by forgetting we are more than our psychological subjectivity—and to be bodily is to be capable of motion. Now, everything capable of motion is said either to move or to be moved; and whatever can be said to move can also be said to be moved, but not vice versa. To be capable of motion, therefore, does not necessitate that one move oneself, only that one be receptive of the state of motion. Ours, however, is to move; we are self-moving—thus able to be moved as well—and the dissociation of this truth from the conception of the self builds up into the need for cathartic action.
And so to understand ourselves we must ask: what is motion?
“…ἡ τοῦ δυνάμει ὄντος ἐντελέχεια, ᾗ τοιοῦτον”, said Aristotle in the mid-4th century bC—“the being-at-work-staying-itself of whatever is potentially, just as such” —and almost twenty centuries later, Descartes demurred; for his was an idealist mind that could not grasp the realist Aristotelian definition any better than could Pierre Gassendi’s. Structured as Descartes’ thought was by his desire for mathematical purity, motion—to him—had to be defined in dependence upon place, and place in reference to space, with space being conceived through the innately ever-present concept of extension… which is itself only a concept of that wherein bodies may be found. Thus, place is defined as the relative position of potential occupation of space,  and motion as “the action by which any body passes from one place to another”;  a definition that says nothing about what motion is, only how it may be understood against the backdrop of “space” [furthermore (mis)taken as an innately given idea, rather than as the abstraction of extension from the extended].
But had Gassendi and Descartes understood the metaphysical principles of act and potency—and that act and potency are of two kinds each—or hunted down the meanings of the Greek term ἐντελέχεια rather than reach for its enervated Latin translation as actualitas, then Aristotelian physics would not have been so usurped,  and possible our conception of the self might not ring quite as hollow.
A great insight into the reality of act lurks in the complex etymology of Aristotle’s neologism ἐντελέχεια, “being-at-work-staying-itself”. It is a combination of ἐν—a form of the Greek for “being”, τέλος, the “end” or the “purpose for-which” something exists—and ἔχειν, the continued having or holding; filtered through the then-common word ἐνδελέχεια, persistence (from which it differed by having Aristotle swap out a delta-δ for a tau-τ, to import τέλος into the word), and aping the structure of the more common and similarly translated ενέργεια, or “being-at-work” (which also combines ἐν and the word ἔργον, “work”). That both words—ἐντελέχεια and ενέργεια—were translated into Latin as actualitas and English as “actuality” has undermined the understanding of Aristotle for centuries.  In its ambiguity, actualitas fails to capture the distinction between ἐντελέχεια and ενέργεια, and the wealth of meanings in their etymologies.
Being-at-work: that is, not necessarily the exertion of a transitive action—an act that “goes out” from a being into the world outside it—but any exertion of effort whatsoever, even if it’s nothing other than the continued exertion of being what-a-thing-is (even if that thing is no more than a lump of matter waiting for something else to act upon it, like an errant rock suspended idly between galaxies.) This is an immanent act: one that remains within the being of which it is an act; but so too, every transitive action, such as pushing open a door or stomping one’s foot or stroking a beloved’s hair, is ενέργεια. Yet there is something else and something more to the kinds of acts we may have; that is, being-at-work-staying-itself: which is that act whereby a thing is-what-it-is and continues being-what-it-is, in its very nature and in accord with its very purpose—that act which unites formal and final cause in the same being. This is always an immanent act, but one which may comprise the consequences of countless transitive actions.
So what is the being-at-work-staying-itself of a potency—just as such, that is, insofar as it is a potency? To answer requires we get a grasp on its aforesaid twofoldness. On the one hand, potency is a being’s capacity to exert itself in an act of ενέργεια, as the extra-galactic rock has a potency to be moved, or the robin a potency to make a nest. But potency is also that-which-is-not-yet but might be—the proximate unrealised that could become.  This sort of potency is thus the being-at-work-staying-itself of a (capacitive) potency, insofar as it is a(n as-yet unrealised) potency, or what might be considered a kind of “privation”—some way in which the being could be, but is not yet.  For instance: I have the capacity to walk, and so there is a potential that I might move myself (capacity) away from my desk and into the kitchen (a current privation), the forest, or the frigid early-spring waters of Lake Erie.  Insofar as I am in the process of so doing—that is, of attempting to realise that privation through an enaction of my capacity—I am moving, and specifically, moving by walking.
This peripatetic mobility is one we sometimes take for granted, not just in the sense that some don’t have it, but for its importance in our lives as mobile beings. Our mobility is, after all, not wholly indeterminate, but consists in the movement of our limbs and, as animals whose proper mode of existence requires that we move from place to place, around object to object, we are walking beings. Barring those who have suffered a loss of the capacity, all of us walk: from room to room, domicile to automobile, car seat to desk chair; for city-dwellers, from store to train to home; and, if we do not hit the magic number that our smartphone apps or fitness bracelets tell us we must to be healthy, we may walk in circles around a parking lot or nowhere on a treadmill.  But all this walking is crammed into the frame of efficient subservience to the self as psychological subjectivity: to being places, being on time, being seen, being with others, to meeting our daily step numbers or caloric burn, to what Heidegger described as the fallenness of Dasein among the unconsciously appropriated intentions of das Man.
In brief, we let ourselves become beings that happen to walk, rather than allow ourselves to be the walking beings we are.
For most of my adult life, I have been a walker: not someone who walks to get from place A to place B, but someone who walks because to walk is a part of being human. Though I may incidentally stop in at a bookstore or bar, these are merely detours, for my walking habit grew away from them, frequently removed even from buildings, in the dense woods of north Georgia. My undergraduate institution sat there, quiet and isolated, away from busy roads and city life and human society, with a softly serrated horizon of the Appalachian Mountains and a night sky clear enough to see the Milky Way. One could set out from campus to the east, west, or south and, with the right path, traipse a mile or five without encountering another human soul, but plenty belonging to rabbits, birds, deer, even the occasional track of a mountain lion. My feet carried me not just through Arcadia but also Walden, not only down the concrete paths that led to the intellectual freedom of the liberal arts, but through gullies and over boulders possibly untouched by any human being in living memory that led to an awareness of the self as animal—and, surely, to a deeper sense of the self as animal-that-understands.
I saw a world untrammelled by human imposition, absent the arbitrariness of schedule or subordination to efficiency, and perfused with a beauty of proportion grossly tarnished by where it was overtaken by industrial avarice. The untouched world is not made to our measure, and to move through it we must adapt ourselves. Walking through the woods, one learns to step differently: to cease the heel-to-toe motion of the city-walker and loosely allow the whole foot to touch the ground, weight evenly distributed; to swivel from the hips in order to increase one’s stride over uneven ground rather than swing the leg; to use one’s arms to balance, brace or grip through difficult terrain. One also learns to perceive more robustly, attending to the angles of the sunlight to keep a sense of direction, ears perked up for the sound of streams and animal movement. Were something to happen—a fall, a dangerous encounter, some injury—there would be no one to help me and possibly nothing to save me. Even the possibility of death became an object of adaptation. 
But the adaptation to environment we gain by walking is not exclusively acquired in the wild. For six years, I lived in Houston, Texas, a massive, sprawled out urban monster that could swallow the landmass of New York City several times over; sweltering with saunaesque humidity and temperatures for no fewer than seven of every twelve months. For the first two of those years, I lived in a dangerous neighbourhood, where walking even in the bright of day exposed one to the risk of being mugged or caught in the crossfire of a gang war. Not incidentally, I loathed the city then. My life consisted in driving everywhere, all the time, slipping from air-conditioned building to air-conditioned car and back again. Over the following four years, however—which entailed moving several times, to neighbourhoods much safer than that first—I found myself walking more and more often, and out of desire, not need. In time, I acclimated to the heat; still unpleasant, but no longer unbearable. There were shops and restaurants and bars and works of art to find, and even episodic urban wildlife—a pasture with a half-dozen horses. So despite the imposition of the post-industrial human stamp, here was life; which, without walking, I would have passed by.
This is also what I came to discover in Boston, despite it being in many ways Houston’s inverse; with the city proper  consisting of a dense metropolis with oft-cold winds and snow that one could walk across (with some determination) from east to west or north to south in a matter of hours. One can walk the Boston Common and the Public Gardens, past the pricey stores and wealthy homes and famous churches of the Back Bay; or along the antiquarian brick sidewalks of Beacon Hill, through the commercial streets of Downtown Crossing, or the many landmarks on the Freedom Trail. Or one could stray off the beaten path, away from the tourist routes, to stumble onto unique shops and restaurants, small, quiet parks, obscure markers of forgotten history, or cemeteries filled with headstones that predated the republic by a century.
When we reduce walking to a mode of transport, we lose something of our own mobility; for while cars, trains, and planes may move us faster and farther, more efficiently, and may even be enjoyed as modes of travel in their own right, their speed and necessary restrictions (rails and lanes and FAA approved flight-plans) are disproportionate to everything else about being human. Confined by vehicles, we see through panes of glass, from fixed paths, with our senses muted and attention to our comfort.
In walking through a city neighbourhood, by contrast, one may see not only what is oriented to the street but what is occluded to the car-bound, to look around corners, peek behind pillars and discover the world according to a human scale of size and speed. We come to know the neighbourhood; the sights too small to notice when whizzing by in a car, the smells, the sources of sounds other than car horns and engines, the rough, firm stone and concrete out of which a block is built.
In strolling through the woods, one does not see the forest as from a plane or as whipping by the windows of a train, but is there among the trees, where rock and root may trip the unwary. We may discover the parts which constitute the whole: streams and rivers, robins and rabbits, the cycle where last year’s decay gives life to this year’s growth—a vitality indifferent to our designs and desires. And in discovering nature, we rediscover ourselves.
For a human being to know something concrete and particular—whether it is small enough to fit in the hand as a chipmunk, a book or a leaf, or as large and variegated as New York or London, the Appalachians or the Sahara—requires examining it from many angles and with many senses. We favour our eyes, though frequently at the expense of the other senses. Is a book nothing more than words stuck on a page, or do the feel of the paper, the cover, not become a part of our experience of it? Who picks up a book and does not turn it over, feel the weight of its spine against the palm, thumb the pages’ edges or, if it is used and aged, inhale its history? Is the picture of a river the same as being there yourself—hearing the rush of its pebbly flow, trailing your fingers against the stream, smelling the damp earth at its banks; seeing it from afar, from above, and from the far side? Is there a purpose to the country house if one remains ignorant of the country in which it sits? Do we know a city if we go directly from appointment to appointment, always taking the shortest route possible? Do we truly move ourselves if we are only moved by ends divorced from motion?
 The cathexic dimension of our existence—the feelings and emotions consequent to our perceptions and intellections—likewise forms a part of this disembodied “thinking thing”, though in acts of reflection (the recursive process of which requires explanation exceeding the bounds of this essay.)
 That is, the sum total of our ideas, judgements, feelings, wishes, desires, beliefs, and so on—the kind of “self” one finds in Descartes’ Meditationes.
 Though the error be slight in the beginning, it becomes—as always—great in the end.
 Such was among the concerns raised by Jacques Ellul in his 1964: La Technique ou l’Enjeu du siècle (“Technique, or the Stakes of the century”), somewhat misleadingly translated into English as The Technological Society—that we are ruled now by the increasing permeation of techniques themselves principled by efficiency.
 c.348bc: Φυσικὴ ἀκρόασις, III.1 (201a 11-12).
 1624: Exercitationes paradoxicae adversus Aristoteleos, II.2.4: “The explanation of a familiar thing was requested, but this is so complicated that nothing is clear anymore”. At least Zeno of Elea had the excuse of dying nearly a century before Aristotle was born.
 i.1644-47: Principia Philosophiae, II.10-15.
 i.1644-47: Principia Philosophiae, II.24.
 Descartes 1641: Letter to Mersenne, 28 January, “On J.B. Morin’s Proof for the Existence of God”, 298/96: “I will tell you, between us, that these six meditations contain all the foundations of my physics. But it will not do to say this, if you please; for those who favor Aristotle would perhaps find it more difficult to approve of them. And I hope that those who read them will accustom themselves insensibly to my principles, and will recognise the truth before noticing that they destroy those of Aristotle.”
 Joe Sachs has admirably explained the importance of recovering the original meaning of Aristotle’s language. See his commentaries in his translations of Aristotle’s Physics: A Guided Study (Rutgers University Press, 1995) and Metaphysics (Green Lion Press, 2002) as well as his article on the Internet Encyclopedia of Philosophy, “Aristotle: Motion and its Place in Nature” for fuller expositions of the etymology.
 That is, we distinguish between possibility, as the non-contradictory could-be, and potency or potentiality, as the what that a being having a capacitive potency might do.
 Per Aristotle, and after him, Thomas Aquinas, every physical, sublunary being is composed from form, as the principle of act, and matter, as the principle of potency; the matter of a thing is its capacity to be otherwise, while its privation is the otherwise that it could be—a different form that it could take on, either accidentally (as blonde hair may become blue) or substantially (as a living thing may become dead); and to explain how a thing changes, we need to understand this twofold potentiality, both as a property of the thing in its current state, and as another form which it could be but is not yet.
 Cf. Kemple 2019: Introduction to Philosophical Principles, 38-45, 62-66.
 Cf. Nolen Gertz 2018: Nihilism and Technology, c.5, especially 93: “Moving for the sake of moving, or even for the sake of ‘fitness,’ means that it is the numbers that matter, not the person behind the numbers. In fact, there is no person behind the numbers. At least not to the extent that ‘person’ means anything other than what is measurable, what is translatable into data.”
 Indeed, not terribly far from campus but too far to be heard, I did once fall into a gully out of which it seemed I might never escape; one end blocked with impassable brambles, and the sides—over my head—crumbled whenever I grasped the ledge. As daylight gave way to dusk and the recollection of large paw prints grew in my mind, I knew that if I wanted to live, there might be no escape but that I could contrive; and so, noting a thin root protruding from the gully’s side, I clawed at the dirt until I found a root substantial enough to hoist myself to safety.
 I walked much of Cambridge and Somerville, too, but cared for it less—populated as it is by an excess of college students, whose hateur is frequently derived not from any genuine personal merit, but for having been admitted to one or another prestigious institution.
Brian Kemple is the author of Ens Primum Cognitum in Thomas Aquinas and the Tradition and The Intersection of Semiotics and Phenomenology. He received his PhD in Philosophy with the Center for Thomistic Studies at the University of Saint Thomas, Houston TX, in 2016, and is the only student ever to complete a dissertation under the direction of John Deely. He currently consults as a Research Fellow with the Center for the Study of Digital Life (www.digitallife.center) and operates a private philosophical consulting and education service, Continuum Philosophical Insight (www.cp-insight.com).